And if you want to make make the statement that she owns two dogs, you can use the following statement (OWL 2 Functional Syntax):
ClassAssertion( ObjectCardinality( 2 gr:owns vocab:Dog ) :Alice )
Cheers,
Denny
On Dec 17, 2010, at 10:59, Martin Hepp wrote:
> Hi Melvin,
> my two cents ;-) :
>
> 1. For owns, there is already a property read for use: http://purl.org/goodrelations/v1#owns
>
> 2. As Dave indicates, the irritation comes from the difference between "a" in English and in Turtle. In English, it's a quantifier, in Turtle it means "instance of".
>
> 3. Using DBPedia URIs as classes is problematic, because they usually represent topic instances. But Yago or Cyc will provide nice classes for dogs.
>
> 3. BNodes and resources identified by a full IRI both leave open whether both dogs are the same, so
>
> foo:Fix a vocab:Dog .
> foo:Foxy a vocab:Dog .
> foo:Alice gr:owns foo:Fix, foo:Foxy .
>
> does not yet make clear that these are two dogs; it could also just be two names / two identifiers for the same entity.
>
> For stating that, you would have to use owl:differentFrom :
>
> foo:Fix owl:differentFrom foo:Foxy .
>
> Then you could infer that she owns at least two dogs.
>
> Best
> Martin
>
>
>
> On 17.12.2010, at 10:30, Dave Reynolds wrote:
>
>> On Fri, 2010-12-17 at 09:55 +0100, Melvin Carvalho wrote:
>>> Apologies if this has come up before. I was wondering the best way to
>>> model the following:
>>>
>>> Alice owns a dog. We choose to model it as follows.
>>>
>>> :Alice :owns a dbpedia:dog
>>
>> That's an RDF statement, maybe you meant:
>>
>> :Alice :owns [a dbpedia:dog] .
>>
>> I.e. there is something, which is a dog and which Alice owns.
>>
>>>
>>> All is going well.
>>>
>>> Then Alice gets given a second dog.
>>>
>>> If we write:
>>>
>>> :Alice :owns a dbpedia:dog
>>> :Alice :owns a dbpedia:dog
>>
>> :Alice :owns [a dbpedia:dog] .
>> :Alice :owns [a dbpedia:dog] .
>>
>> is a reasonable graph, it is not lean since both those bNodes might
>> correspond to the same dog but it is a graph with 4 statements not a
>> graph with two statements.
>>
>> To convey that those are definitely different dogs then you can add an
>> owl:differentFrom link:
>>
>> :Alice owns _:1 .
>> _:1 a dbpedia:dog .
>> :Alice owns _:2 .
>> _:2 a dbpedia:dog .
>> _:2 owl:differentFrom _:1 .
>>
>> Dave
>>
>>
>>
>
>